1. Field of the Invention
This invention pertains to an apparatus which can be used to prepare sample slides from cell suspensions in a centrifuge.
2. Description of the Prior Art
Standard medical diagnostic procedures in fluid sample analysis can involve withdrawal of spinal, abdominal or pleural fluids from a patient in order to analyze such fluids for the presence of, e.g., cancer cells. Such fluids contain a relatively large amount of supernatant fluid in which the cells to be examined are suspended. It is critical to retain the maximum number of cells when separating them from the supernatant fluid in order to avoid the necessity of taking a second sample from a patient, or alternatively basing medical diagnosis and treatment upon a sample from which abnormal cells may have been lost.
Known methods of separating cells from the supernatant fluid in the sample involve either enhanced sedimentation of the sample through controlled diffusion into a filter paper, or centrifugation of the sample. In the former case, cell loss to the filter paper can arise, and a substantial sample size is required. In the latter case, a sample-containing tube is centrifuged, and the topmost layer of supernatant fluid is decanted, leaving the bottom fluid available for examination. Because this latter method involves the possibility of cell loss and also requires a relatively large sample size, it is also disadvantageous.
Moreover, neither of these two methods allows cells to be collected directly upon a conventional glass slide. Inasmuch as the cells collected from such samples are subjected to microscopic analysis, it would be advantageous to provide a device which would not only allow a relatively small sample to be withdrawn from a patient and which would allow all cells therein to be collected, but which would also allow these cells to be collected directly upon a conventional glass slide so that no intermediate transfer of collected cells thereto would be necessary prior to microscopic examination.